Spark-plug.



H. M.- SPENCER.

SPARK PLUG. APPLICATION FILED 00T. B. 1912.

1,077,960, Patented Nov. 4, 1913.

if ZI Inventor Attorneys YUTE Y HARRY M. SPENCER, OF DUNMORE, PENNSYLVANIA.

SPARK-PLUG.

Specicaticr. cf Letters Patent.`

Latented Nov. 4,' 1913.

Application-'mea come: 1512. se-fiai No. 724,591.

Toall whom t may concern l tion.

Fig. 2 is a'vertical central sectional Be it known that HARRY M. SPENGER, l v iew therethrough. Fig. 3 is a bottom plan citizen of the United States, residing at Bunmore, in the county of Lackziwanna and State of Pennsylvania, have invented a new and useful Spark-Plug, of which the following is l sulating member disposed 1n the lower end a specification. f. l

The present invention' relates to improvements in spark plugs:

The primary object of this invention is the provision of a novel form "of spark plug, 1n which the air gap between the relative sparking elements at the lower end of the plug 1s sealed by an insulating member, said msulating member being so disposed as to expose a plurality of sparking terminals upon the stationary member so that the coactic-n therewith of a plurality of rotatably mounted sparking terminals of the opposed member willbe disposed in adjustable relation to the stationary 'sparking terminals and so that when the rotary members are rotated, the exposed surfaces of the stationary sparking terminals and insulating member may be scraped, thus cleaning the accumulated carbon therefrom without the necessity of removing the plu from the cylinder. l

A further object of the present invention is the provision in a sparkplug of a stationary electric element provided with a plurality of concentrically'disposed sparking terminals in combination with a vrotatably mounted stem carrying a plurality of sparking terminals, said .terminals being in coactive relation both for adjusting and clean- 1 ing relatively to the stationary terminals and being guided in its movement'during rotation by an insulating membel` disposed to ll the air gap between the concentrically disposed terminals and the insulating body carrying the stem, the rotation of the stem and terminals carried thereby cleaning simultaneously both the exposed ortion of the stationary terminals Aand the insulation.

Vith the foregoing and other objects in view whichwill appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of constructin hereinafter described and claimed it being understood that changes in the precise embodiment of the invention herein disclosed can be made within' the scope of what is claimed without departing from the spirit of the invention.

In the ,drawings-Fi re 1 is aside'elevaview of the plug as illustrated in Fig. 1. Fig. et is a perspective view of the lower end of the rotary terminal Ycarrying member. lig.- 5 is a detail perspective view of the inof the plug.

Referring to the drawings, the numeralll designates the metal bushing which is provided with the threaded portion 2 for engagement with the plug socket of anexplosive engine, the lower end of which is provided with a plurality of tapered sparking terminals 3, preferably fou'r in number, the lower edges of which at the spark gap portion being inclined as at 4, t-he purpose of which will presently appear.

Mounted wirt-hin the bushing 1 is a sleeve or tube of insulation 5 in whose bore 6 is disposed a metal casing or sleeve 7 having the enlarged socket or cavity '8 in 'the lower end thereof, while the lower end of the insulating bushing or sleeve 5 is reduced as at- 9 to produce a concentric cavity 10 between the adJacent face thereof and the inner wall of the bushing 1. In mest spark plugs, this space forms an air gap and is not sealed,I

and it has been found advantageous to seal the space and form a continution upon the lower end of thesleeve 5, this being accomplished by the insulating member 12, whose ring 11 is disposed to tit about and incase the lower endv of the sleeve 5, as clearly shown in Fig. 2 and fill the space therebelow and adjacent to and between the sparking terminals 3, the lower end of the'insulating member 12 being provided Awith the convoluted portions 13 and 14 which form a guiding means for the rotary sparking terminals 19, as will A presently appear.

This insulat;I`

ing member 12 is composed of lava oriothr insulating substance that will withstand the Disposed for rotation within the bore of the bushing 7' is a stem 17, upon Whose lower end is mounted or carried, the enlarged cylindrical portion 18 fitted for sliding and rotary movement within the socket 8 of the sleeve 7 and carried upon the lower end of the cylindrical portion 18 and disposed to ride upon the convoluted portions 13 and 14 of the insulating member 12 and being disposed in sparking relation to the sparking terminal portions 4 of the stationary terminals 3, are the sparking terminals or arms 20, each one of which 1s rovided with the inclined face 19 disposed ihr coaction with the inclined face 4 of its respective terminal 3. By this means, the terminals 19 may be readily adjusted to secure the desired spark. between the faces 4 and 20 and when it is desired to clean such faces 4 and 2O and also the lower face of the insulating member 12, of any accumulation of carbon thereupon, the stem 17 is rotated in the direction of the arrow Fig.

1 so that'the upper edge of the respective arms 19 will act as a cutting means and also a scraper riding upon the long curved lportion 13 between the respective terniinals 3 and finally upon the shouldered portion 14 before finally engaging the inclined portion 4 of the respective terminals 3, the. spring 21 exerting a normal tension against the locking disk 22 to hold the terminals-19 upwardly against the insulating member l2 and the terminals 3 during the rotation of the stem through the keyed milled disk 23 mounted upon the upper end of the stem 17. The disk 22 and lock nut or disk 24 constitute a binding post for holding the electric terminal 25 in position.

A locking cap 26 is placed upon the upper end of the insulating bushing or sleeve 5 and is provided with a socket 27 for assisting in maintaining the spring 21 in its necessary position.

From the foregoing description, taken in connection with the drawings it 1s evident with a spark plug constructed according to the present invention, that. the terminals 19 may be adjusted to accomplish the best possible result` without the necessity of the removal of the plug from the engine cylinder and that when it is necessary to clean the carbon from the under surface of the termiinsulati n jarring of the engine will in no way disturb the adjustment.

lVh'at is claimed is: l

1. A spark plug, including a metal bushingsprovided upon its lower end with a sparking terminal, an insulating body sealing the lower end of the bushing and partially embracing the terminal to provide a single exposed face to the terminal, said exposed face being flush with the face of the body, a stem mounted for rotation Within the insulating body, a sparking terminal carried upon the lower nd of the stem, and means for maintaining the stem and its terminal in adjusted relation with respect to the terminal of the bushing.

2. A spark plug, including a metal bushing having a plurality of sparking terminals, an insulating sleeve mounted in the bushing and terminating within and out of contact with the lower end of the bushing, a bodyof insulation fitted in the lower end of the bushing and about the lower end of the insulating sleeve, the lower face of said body being below the bushing and partially surrounding the terminals, whose sparking faces are exposed through the body of insulation, and a plurality of rotatable sparking terminals disposed in sparking relation to the exposed ends of the terminals of the bushing and forming a cleaning means -for the lower face of the insulation body and stationary terminals when rotated.

3. A spark plug, including a metal bushing having a plurality of sparking terminals, an insulating sleeveniounted in the bushing and terminating within and ont of contact with the lower end of the bushing, a body of insulation fitted within the lower end of the bushing and about the lower end of the insulating sleeve, the lower face of said body being below the bushing and partially surrounding tbe terminals, whose sparking faces are exposed through the body of insulation, a stem rotatably mounted within the insulating sleeeve and operable from the upper end thereof, and a plurality of sparking terminals carried upon the lower end of said stem for coaction'with the exposed faces of t-lie terminals of'thc bushing. said stem carried terminals when rotated scraping the lower surface of thc body of insulation and exposed ends of the terminals of the. bushing to clean the same.

4. A. spark plug. including a metal bushing having a plurality of sparking terminals, an insulating sleeve mounted in the bushing and teri'ninating within and ont of contact with the lower end ot the bushing. a body of Iinsulation fitted in the lower end of the bushing and about the lower end of the. insulating sleeve, the lower face of said body being below the bushing and par tially surrounding the terminals, whose sparking faces are exposed through the body of insulation, a plurality ofrotatable sparking terminals disposed in sparking relation tothe exposed ends of the termina-ls of the bushing and forming a cleaning means for the lower face of the insulation body and stationary -terminals when rotated, andmcans for resiliently holding the rotarysparking terminals toward and in contact with the terminals of the bushing and insulating body when rotated and against the insulating body when stationary.'

5. A spar-k plug, including a metal bushing having a plurality of sparking termi-k from the upper end thereof, a plurality. of

vsparking terminals carried upon the lower end of said stem for coaction with the eX- posed faces of the terminals of the bushing, said stem carried terminals when rotated scraping the lower surface of the body of insulation and exposed ends of the terminals of the bushing to clean the same, and means for resiliently holding the rotary sparking terminal toward and. in contact with the terminals of the bushing and insulating body whcnrotated and against the insulating body when stationary.

C. A spark plug, including a metal bushing having a plurality of sparking terminals l'rrojecting from the lower'end thereof, each terminal being provided with an inclined-V sparking Aface upon the lower end thereof, an insulating body mounted i-n Ithe bushing throughout the length thereof and partially incasing the lower end of the bushing and the adjacent portions of the sparking terminals, the inclined faces of the sparking terminals beingr exposed through the insulating body, a stem mounted for rotation within the insulating body, a plurality of spark ing terminals carried upon the lower end of said stem one to each sparking terminal of the bushing, the sparking surfaces of said Aterminals being disposed at an incline parallel to the incline of the respective terminals of the bushing, and means for rotating said stem and' terminals to clean the lower exposed faces of the insulating body and stationary terminals.

7. A spark plug, includingja metal bushing having a plurality of sparking terminals projecting from the lower end thereof, each terminal being provided with an inclined sparking falce upon the lower end thereof,

an insulating body mounted in the bushing throughout the length thereof and partially incasing the lower end of the bushing and the adjacent portions of the sparking terminals, the inclined faces of the sparking terminalsbeing exposed through the insulating body, a stem mounted for rotation within the insulating body, a plurality of sparking terminals carried upon the lower end of said stem, one to each sparking terminal of the bushing, the sparking surfaces of said terminals being dispose-d at an incline parallel to the incline of the respective terminals of the bushing, means for rotating said stem and terminals to clean the lower eX- posed faces of the insulating body and sta-l tionary terminals, and' means for resilicntly holding the stem and termina-ls toward the bushing and insulating body.

8. A spark plug, including a metal bushing having a plurality of sparking terminals projecting from the lower end thereof, each terminal being provided with an inclined sparking face upon the lower end thereof, an insulating body mounted in the bushing throughout the length thereof and partially incasing the lower end of the bushing and the adjacent-portions of the sparking terminals, .the inclined faces of the sparking terminals being exposed through the insulating body, a stem mounted for rot-ation within the insulating body, a plurality of sparking .terminals carried upon the lower end of said stem oneV to each sparking terminal -of the bushing, the sparking surfaces of said terminals being disposed at an incline parallel to the incline of therespective terminals of the bushing, means for rotating said stem and terminals to clean the lower exposed faces of the' insulating body and stationary terminals, and means for resiliently holding the stern and terminals toward the bushing and insulating body,- said vterminals of the stem being normally held against the insulating body and in sparking relation to the respective terminals ofthe bushing,

l9. A spark plug, including a metal bushing having a plurality of sparking terminals projecting from the lower end thereof, each terminal being provided with an inclined sparking face upon the lower end'thereof, an insulating body mounted in the bushing throughout the length thereof and partially incasing the lower end of the bushing and -the adjacent portions of the sparking terminals, the inclined faces of the 4sjgiarking terminals beingexposed through the insulating body, a stem mounted for ,rotation wit-hin the insulating body, a plurality o`f sparking terminals carriedupon the 4lower end of said stem, one to "each sparking terminal of the bushing, the sparking surfaces of said terminals being disposed at an in- .'cljne parallel to the incline of therespective terminals of the bushing, means for rotating exposed faces, of the insulating body and stationary terminals, and means for resiliand stationary terminals, and means for resaid stem and terminals to clean the lower ently holding the stem and terminals toward the bushing A.and insulating body, the lower end of the insulating body between the re spective termina-1s of the bushingbeing convoluted'to forni a guiding means for the terminals of the stem during the rotation thereof when cleaning the insulating body and exposed faces of the stationary terminals.

10. A spark plug, including a metal bushing having a plurality of sparkingterminals projecting from the lower end thereof, each terminalbeing provided with an inclined sparking face upon the lower end thereof, an insulating body mounted in the bushing throughout the length thereof and partially incasing the lower end of the bushing and the adjacent portions of the sparking terminals, the inclined faces of the sparking terminalsvbeing exposed through the insulating body, a stem mounted for rotation within the insulating body, a plurality of sparking terminals carried upon the lower end of said stem one to each sparking terminal of the bushing, the sparking surfaces of said terminals being disposed at au in* eline parallel to the incline of the respective terminals of the bushing, means for rotatingsaid stem and terminals to clean t-he lower exposed faces of the insulating body siliently 'holding the stem and terminals toward the bushing and insulating body, said terminals ofthe stem being normally held against the'insulating body and in sparking .relation to the respective terminals of the bushing, the lower end of the insulating body between the respective terminals of the 4bushing being convoluted to form a guiding means for the terminals of the stem during the rotation thereof when cleanin the insulating body and exposed faces o the stationary terminals. A

11. A spark plug, including a metal bush ing provided upon its lower end with apluy rality of sparking terminals, an insulating body sealing the lower end of. the bushing and partially incasing said terminals to provide a single exposed face to each terminal flush with the face of the insulatingmember,

body sealing the lower end of the bushing and partially incasing said terminals to provide a single exposed-face to each terminal flush with the face of the insulating mem ber, a stem mounted for-rotation withintheinsulating member, a plurality of sparking terminals carried upon the lower end there of, one to each terminal of the bushing, and resilient means for maintaining thestem and terminals in adjusted relation with the re? spective terminals of the bushing andfor resiliently holding the stem and its termi nals in relative `position to the terminals of the bushing and insulating body.

In testimony thatI claim the foregoing as my own, I have hereto affixed my signature'in the presence of two witnesses.

HARRY- M.I SPENCER.

Witnesses: f

THos. J. CAVANAUGH, HAZT.Ino1N.

' Copies of this patent may be obtained for five cents each, by addressing the Qommisioner of Patents,

` Washington, D. C.' *i 

